Human heart

The human heart provides a continuous blood circulation through the cardiac cycle and is one of the most vital organs in the human body. It is divided into four chambers: the two upper chambers are called the left and right atria and two lower chambers are called the right and left ventricles. Normally the right ventricle pumps the same blood amount into the lungs with each bit that the left ventricle pumps out. Physicians commonly refer to the right atrium and right ventricle together as the right heart and to the left atrium and ventricle as the left heart.

The electric energy that stimulates the heart occurs in the sinoatrial node, which produces a definite potential and then discharges, sending an impulse across the atria. The Purkinje fibers transmit the electric charge to the myocardium while the cells of the atrial walls transmit it from cell to cell, making the atrial syncytium.

The human heart and its disorders (cardiopathies) are studied primarily by cardiology.